1. Field of The Invention
The present invention relates generally to an improved pack unit for rotary finishing wheels, car wash curtains and the like, and more particularly to a replaceable, one piece, hinge-type, slot-engaging pack unit which can be replaceably mounted on either a curtain-forming structure or a rotary finishing wheel without the use of rod elements or intermediate slot-engaging clip members.
The invention finds use in any type of rotary finishing wheel structure such as those employing abrasive sheets, bristles, or the like which are generally used for grinding, rough or finish abrasive working, brushing, burnishing, and the like. However, in the preferred embodiment of this invention, the improved pack units are employed in commercial automotive car washing establishments for replaceable mounting to form curtain structures or finishing wheel structures, either of which may serve in washing, drying, buffing, polishing, or otherwise finishing the car.
2. Description of The Prior Art
My own U.S. Patents are typical of the rotary finishing wheel structures and pack units of the prior art to which this invention relates and the numbers and issue dates of those patents are as follows: 3,455,068, July 15, 1969; 3,535,833, Oct. 27, 1970; 3,621,622, Nov. 23, 1971; 3,626,646, Dec. 14, 1971; 3,685,217, Aug. 22, 1972; 3,768,214, Oct. 30, 1973; 3,772,833, Nov. 20, 1973; 3,798,847, Mar. 26, 1974; 3,800,481, Apr. 2, 1974; 3,807,099, Apr. 30, 1974; 3,813,829, June 4, 1974; 3,820,291, June 28, 1974; 3,842,547, Oct. 22, 1974; 3,914,908, Oct. 28, 1975; and Re 28,118, Aug. 20, 1974.
Generally, the pack units of the prior art have been replaceably attached to the finishing wheel structure by sliding an elongated rod through a clamp member fastened to the finishing material portion of the pack unit or through a bight portion of one or more of the plies of the pack unit, the bight portion often containing a cylindrical rod-receiving tube or U-shaped rod-receiving member. While a few of the pack units of the prior art are adapted to directly engage a slot on the periphery of the wheel, all of these pack units require an external clamping member having one portion for securing the flaplike plies of finishing material together and a second portion adapted for engaging the slots of the wheel.
Both the mounting means which requires an insertable rod and usually a rod-receiving clamp member secured to the flap-like pad members and the technique which requires a separate, normally metallic, clamp member, one end of which secures the flap-like finishing pads while the other end is adapted to engage the slot, are relatively expensive and it is often difficult or time-consuming to replace the pack units.
The improved modular pack unit of the present invention employs a relatively inexpensive, easy to replace construction which does not employ any type of external clamping member and does not require the use of insertable mounting rods or the like.